Earthen evaporative heat exchanger

ABSTRACT

A heat exchanger with earthen material for cooling ambient air may serve as an energy efficient alternative to air conditioning. The heat exchanger may take in ambient air and cool the air through evaporative heat exchange, which may be very useful during summer months in areas where the day temperatures can be very high. A fan may be used to provide airflow through an evaporating heat exchanger, which results in an airflow that is much cooler than the ambient temperature. The heat exchanger may be made from an earthen material, such as fired clay, for example, with a large surface area coming into contact with the airflow. One or more cavities may be present in the heat exchanger to hold water and allow the water to percolate through the porous earthen material.

BACKGROUND OF THE INVENTION

The present invention relates to heat exchangers and, more particularly, to an evaporative heat exchanger with earthen material for cooling ambient air.

Conventional air conditioners require considerable energy due to the use of compressor technology. A compressor is typically used to compress a gas (such as Freon, or some other fluorinated hydrocarbon, for example) into a liquid. This liquid is allowed to encounter a reduced pressure area, such as a heat exchanger coil, where the liquid becomes a cold gas. The gas passes back to the compressor to repeat the cycle. This continual compression uses a substantial amount of energy.

As can be seen, there is a need for an apparatus and method for cooling air that may use a minimal amount of energy.

SUMMARY OF THE INVENTION

In one aspect of the present invention, a heat exchanger comprises an earthen heat exchanger element; a reservoir in fluid connection with at least a portion of the earthen heat exchanger element; and a plurality of holes in the earthen heat exchanger element, the holes adapted to allow air to pass through the heat exchanger.

In another aspect of the present invention, a heat exchanger comprises an earthen heat exchanger element; a reservoir in fluid connection with at least a portion of the earthen heat exchanger element; at least one water conduit formed in the earthen heat exchanger element, the water conduit in fluid communication with the reservoir and a plurality of holes in the earthen heat exchanger element, the holes adapted to allow air to pass through the heat exchanger.

These and other features, aspects and advantages of the present invention will become better understood with reference to the following drawings, description and claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a heat exchanger according to an exemplary embodiment of the present invention;

FIG. 2 is a perspective view of a heat exchanger according to another exemplary embodiment of the present invention;

FIG. 3 is a perspective view of the heat exchanger of FIG. 1 is use with a fan;

FIG. 4 is a schematic cross-sectional view of a heat exchanger according to another exemplary embodiment of the present invention;

FIG. 5 is a perspective view of the heat exchanger of FIG. 1 used in an air conditioning application; and

FIG. 6 is a perspective view of the heat exchanger of FIG. 4 used in an air conditioning application.

DETAILED DESCRIPTION OF THE INVENTION

The following detailed description is of the best currently contemplated modes of carrying out exemplary embodiments of the invention. The description is not to be taken in a limiting sense, but is made merely for the purpose of illustrating the general principles of the invention, since the scope of the invention is best defined by the appended claims.

Various inventive features are described below that can each be used independently of one another or in combination with other features.

Broadly, an embodiment of the present invention provides a heat exchanger with earthen material for cooling ambient air. The heat exchanger may serve as an energy efficient alternative to air conditioning. The heat exchanger may take in ambient air and cool the air through evaporative heat exchange, which may be very useful during summer months in areas where the day temperatures can be very high. In some embodiments, a fan may be used to provide airflow through an evaporating heat exchanger, which results in an airflow that is much cooler than the ambient temperature. The heat exchanger may be made from an earthen material, such as fired clay, for example, with a large surface area coming into contact with the airflow. One or more cavities may be present in the heat exchanger to hold water and allow the water to percolate through the porous earthen material.

Referring to FIG. 1, a heat exchanger 10 may include a reservoir tank 12 adapted to contain a liquid, such as water, and an earthen heat exchanger element 14. The reservoir tank 12 may be in fluid contact with at least a portion of the earthen heat exchanger element 14. A plurality of holes 16 may be disposed through the earthen heat exchanger element 14. Air may be passed through the heat exchanger 10 by, for example, a fan 24, as shown in FIG. 3. A plenum 22 may control the flow of air from the fan 24 to the heat exchanger 10. The earthen heat exchanger element 14 may be made from a porous material, such as fired clay, potter's clay, mud-based clay, terra cotta, adobe, or the like.

As the air is pushed through the holes 16, the air may evaporate water that has percolated through the earthen heat exchanger element 14. This evaporation may cool the air. As the water from the reservoir 12 evaporates in the heat exchanger 10, water may be replenished. In some embodiments, a water level measurement device (not shown) may be disposed to automatically refill the reservoir 12 as needed.

The style of the heat exchanger 10 may vary. For example, as shown in FIG. 2, a heat exchanger 11 may include an earthen heat exchanger body 18 with a plurality of fins 18 formed therein. In other embodiments, a heat exchanger may include fluid tubes (not shown) formed in the earthen heat exchanger element to help deliver water to openings through which the airflow is passing.

The heat exchangers 10, 11 of FIGS. 1 and 2 may be used, for example, as a pre-cooler for ambient air being delivered to an air conditioning system 36 as shown in FIG. 5. In this embodiment, the air conditioning system 36 may be a conventional system having refrigerant conduits 38 to cool a coil (not shown) in the air conditioning system 36. With the heat exchanger 10, 11, the air conditioning system 36 may be required to cool air fewer degrees, thus saving energy costs. For example, a conventional system may take in 80 degree ambient air across a 38 degree coil, cooling the 80 degree ambient air to 68 degrees. With the heat exchanger of the present invention, the 80 degree ambient air may be precooled to, for example, 76 degrees, prior to being delivered to the 38 degree coil, thus cooling the ambient air to, for example, about 65 degrees, thereby needing less air conditioning system running time to cool a room or home.

Referring now to FIGS. 4 and 6, a heat exchanger may include a reservoir tank 27 that is fluidly connected with water conduits 30 through an earthen heat exchanger element 26. The element 26 may include a plurality of holes 28 therethrough. The holes 28 may carry air that is cooled by the heat exchanger. In addition, as water evaporates due to air moving through the holes 28, the water in the reservoir tank 27 also cools. This cooled water may be moved with a pump 32 through conduits 42 into an air/liquid heat exchanger 34. This heat exchanger 34 may be present in a residential or business air conditioning system 40, where air is taken from the location, moved over the heat exchanger 34, and delivered back to the location as cooled air. In some embodiments, the system 40 may cool air without the use of a conventional compressor. In other embodiments, the system 40 may be equipped with a conventional compressor cooled coil (not shown) in addition to the heat exchanger 34, where the conventional compressor cooled coil may be activated only when the air temperature at the location needs additional temperature control.

It should be understood, of course, that the foregoing relates to exemplary embodiments of the invention and that modifications may be made without departing from the spirit and scope of the invention as set forth in the following claims. 

1. A heat exchanger comprising: an earthen heat exchanger element; a reservoir in fluid connection with at least a portion of the earthen heat exchanger element; and a plurality of holes in the earthen heat exchanger element, the holes adapted to allow air to pass through the heat exchanger.
 2. The heat exchanger of claim 1, wherein the earthen heat exchanger includes potter's clay, mud-based clay, terra cotta or adobe.
 3. The heat exchanger of claim 1, wherein the holes are formed between fins in the heat exchanger.
 4. The heat exchanger of claim 1, further comprising: a plenum directing air into the plurality of holes; and a fan for moving the air through the plurality of holes to supply a cooled air.
 5. The heat exchanger of claim 4, wherein the cooled air is delivered to an air conditioning system.
 6. The heat exchanger of claim 4, further comprising at least one water conduit formed in the earthen heat exchanger element, the water conduit in fluid communication with the reservoir.
 7. The heat exchanger of claim 1, further comprising a pump for circulating water in the reservoir through an air/liquid heat exchanger.
 8. A heat exchanger comprising: an earthen heat exchanger element; a reservoir in fluid connection with at least a portion of the earthen heat exchanger element; at least one water conduit formed in the earthen heat exchanger element, the water conduit in fluid communication with the reservoir and a plurality of holes in the earthen heat exchanger element, the holes adapted to allow air to pass through the heat exchanger.
 9. The heat exchanger of claim 8, further comprising a pump for circulating water in the reservoir through an air/liquid heat exchanger.
 10. The heat exchanger of claim 9, wherein the air/liquid heat exchanger is disposed in a cooling system, the cooling system forcing air across the air/liquid heat exchanger to provide a cooled air. 